Zhang Wenyu, Zhou Zhifang, Yang Yueyang, Zheng Yunpeng, Xu Yushuai, Zou Mingchu, Nan Ce-Wen, Lin Yuan-Hua
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
Materials (Basel). 2022 Mar 11;15(6):2096. doi: 10.3390/ma15062096.
Because of the high carrier concentration, copper telluride (CuTe) has a relatively low Seebeck coefficient and high thermal conductivity, which are not good for its thermoelectric performance. To simultaneously optimize carrier concentration, lower thermal conductivity and improve the stability, BiCuTeO, an oxygen containing compound with lower carrier concentration, is in situ formed in CuTe by a method of combining self-propagating high-temperature synthesis (SHS) with spark plasma sintering (SPS). With the incorporation of BiCuTeO, the carrier concentration decreased from 8.1 × 10 to 3.8 × 10 cm, bringing the increase of power factor from ~1.91 to ~2.97 μW cm K at normal temperature. At the same time, thermal conductivity reduced from 2.61 to 1.48 W m K at 623 K. Consequently, (CuTe)-(BiCuTeO) composite sample reached a relatively high value of 0.13 at 723 K, which is 41% higher than that of CuTe.
由于碲化铜（CuTe）的载流子浓度较高，其塞贝克系数相对较低且热导率较高，这对其热电性能不利。为了同时优化载流子浓度、降低热导率并提高稳定性，通过自蔓延高温合成（SHS）与放电等离子烧结（SPS）相结合的方法，在CuTe中原位形成了载流子浓度较低的含氧化合物BiCuTeO。随着BiCuTeO的引入，载流子浓度从8.1×10降至3.8×10 cm，使得常温下功率因子从1.91增加到2.97 μW cm K。同时，在623 K时热导率从2.61降低到1.48 W m K。因此，（CuTe）-（BiCuTeO）复合样品在723 K时达到了相对较高的0.13值，比CuTe高41%。
